Abstract:

Research centers on assessing the cost competitiveness of mass timber buildings in the U.S. construction market compared to traditional building materials, particularly concrete and steel. The major purpose of this study is to break down the detailed construction cost of mass timber buildings and compare individual costs with other construction options. The research group collaborated with industry practitioners of mass timber buildings in North America in order to collect cost information on their mass timber buildings. Cost information from similar concrete or steel buildings was also be collected from the North American construction industry to compare the cost associated with construction. The study also includes a questionnaire to assess the perception of designers and contractors about the cost and use of mass timber in the industry now and in the future.


Project Duration: 2019-2020

Project Lead: Ingrid Arocho

Student Researcher: Shafayet Ahmed

Facilities: To conduct the cost comparison study, the research team will collaborate with current mass timber industry practitioners in North America. This will ensure that the study reflects the materials, labor and equipment cost prevalent in the United States. The market perception questionnaire will be provided to companies in both North America and Europe to learn from companies with different projects and years of experience using mass timber.

 

Introduction:

The construction industry is considered as one of the most resource intensive industry sectors in the global economy. This makes the industry susceptible to several risks including resource scarcity and changes to commodity prices. The careful selection of materials can aid on the reduction of those risks while improving the performance of construction projects. Timber has been proposed as a good material that can result on greener designs and less energy consumption. Architectural design needs favorable strength-to-density ratio, versatility, and flexibility, making timber comparable with concrete and steel in certain tall building applications. Research has demonstrated that the long-term success of CLT is highly reliant on potential adopters' impression of the material. An important parameter to assess the longevity of a product is to determine its cost competitiveness. Initial construction cost is invariably perceived as being critical and the total on-going cost of operating a building over its whole lifetime is increasingly being recognized as important when selecting materials. Although the concept of mass timber building has been successful in the European market, it has not been adopted extensively by the North American market, especially in the United States. The cost estimation for mass timber buildings is still inaccurate due to the small number of projects available. It is necessary to develop an accurate comparison between the construction cost of mass timber buildings and traditional materials, in particular concrete and steel. Project stakeholders can then make decisions about material selections and project outcomes based on accurate information.


Research Details:

Step 1. Data collection: The first major step of the study will be communicating with construction companies with experience on mass timber buildings in order to obtain the cost information of their projects. While the cost information is obtained, the research team will approach several other companies to obtain cost information of concrete and steel buildings that have comparable design and purpose than the mass timber projects. Cost information will be gathered based on several important components of a building such as substructure, superstructure, earthwork, exterior and interior, mechanical, electrical and plumbing, thermal, and moisture protection. The research team will also conduct a formal interview with industry practitioners to obtain qualitative cost information of the mass timber building projects, including particular situations that directly affected the cost of each project.

Step 2. Questionnaire distribution: Questionnaires will be developed to collect information from designers and contractors. The questionnaires will then be sent to companies in the United States and Canada. A small number of European companies will also be sent questionnaires for reference. The answers to the questionnaires will be used to understand perceptions on cost difference, constructability, and mass timber market performance. 

Step 3. Data analysis: Collected cost data will be analyzed using statistical tools to compare the overall cost performance of the mass timber buildings with concrete and steel buildings. The analysis will include not only the numerical difference of the cost, but also the activities related to those cost differences. The information from the interviews will be used to understand particular differences between projects that could account for cost differences. The questionnaire results will be analyzed to get a closer look to what happens on the industry.

Step 4. Develop conclusions and recommendations: The results from the data analysis will be used to develop a list of factors that directly affect the cost of mass timber buildings. Possible recommendations will be presented to address the cost difference between materials and to improve perception of mass timber.

Step 5. Communicate results: The results of the study will be shared with stakeholders. The conclusions from the cost comparison can be used to improve future estimations and to understand how to reduce costs in the future. The recommendations could be applied to improve mass timber competitiveness.